Psychosis in Parkinson’s disease

General information

• Psychosis in PD may be due to extrinsic (i.e treatment related) and/or intrinsic (i.e disease related) factors
• Risk factors for psychosis in PD include older age, older age at PD onset, advanced disease, cognitive impairment, depression, akinetic-rigid predominant phenotype, sleep disturbances and presence of multiple medical comorbidities
• Hallucinations (most commonly brief, complex visual, non-threatening) occur in 1/3 of PD patients chronically treated with dopaminergic agents
• Delusions occur in 5-10% of treated PD patients and may take the form of paranoid ideation, other well-systematized thematic ideas or misidentification syndromes (eg Capgras syndrome or Fregoli syndrome)

Differential

• Parkinson’s disease medications
• Systemic illness
• Other medication or intoxication
• Hepatic, renal or other metabolic disorder
• Sensory deprivation
• Infection
• Structural brain lesion (eg stroke, trauma)

Workup

Laboratory

• Complete blood count
• Metabolic profile
• Thyroid function
• Toxicology screen
• Urinalysis
• Urine culture
• CSF analysis in selected cases

Imaging

• Chest X-ray
• Head CT or MRI

EEG in selected cases.

Management

• If agitated, sedate with low dose benzodiazepine
• Identify and treat infection or other underlying medical condition
• Avoid rapidly acting antipsychotics
• Reduce or remove non-PD medication that may have psychoactive properties (anticholinergics, antidepressives, hypnotics, opioids are among the most common)
• If no improvement, gradually reduce PD medication starting with the drugs with the highest risk/benefit ratio (anticholinergics, amantadine, selegiline, dopamine agonists, COMT-inhibitors and last, levodopa)
• Consider addition of an atypical antipsychotic. Available evidence suggests clozapine (Level B) or quetiapine (Level C) are the most beneficial
• If antipsychotics are used, start with a low dose. Effective dose for clozapine is 6.25-50 mg/day

References

• Neuropsychiatric symptoms in Parkinson’s Disease. Mov Disord. 2009;24:2175–86.doi: 10.1002/mds.22589
• Diagnostic and statistical manual for mental disorders. 4th ed. Washington, DC: American Psychiatric Association, 1994:739-42.
• Visual hallucinations in Parkinson’s disease: a review and phenomeno- logical survey. J Neurol Neurosurg Psychiatry. 2001;70:727–33. doi: 10.1136/jnnp.70.6.727
• Emergency department presentations of patients with Parkinson’s dis- ease. Am J Emerg Med. 2000;18:209–15 doi: 10.1016/s0735-6757(00)90023-8
• Parkinson’s disease psychosis 2010: a review article. Parkinsonism Relat Disord. 2010;16(9):1–8 doi: 10.1016/j.parkreldis.2010.05.004
• Movement Disorder Emergencies Diagnosis and Treatment, Second edition Humana Press (2013) ISBN 978-1-60761-834-8
• New developments in depression, anxiety, compulsiveness, and hallucinations in Parkinson’s disease. Mov Disord. 2010;25:S104–9. doi: 10.1002/mds.22636
• Double blind, placebo-controlled, unforced titration parallel trial of quetiapine for dopaminergic-induced hallucinations in Parkinson’s disease. Mov Disord. 2005;20:958–63.doi: 10.1002/mds.20474
• Diagnostic criteria for psychosis in Parkinson’s Disease: report of an NINDS, NIMH work group. Mov Disord. 2007;22:1061–8. doi: 10.1002/mds.21382
• The effect of quetiapine on psychosis and motor function in parkinsonian patients with and without dementia. Mov Disord. 2002;17:676–81. doi: 10.1002/mds.10176